Many mobile machines use electrical energy and are equipped with batteries, for example electric vehicles, cherry pickers, pallet trucks, etc. These machines generally comprise on-board chargers, i.e. electric battery chargers which are mounted directly on the mobile machines. They can also be used with an external battery charging device.
The main function of these chargers is to recharge batteries using the available electricity on the electrical distribution network. They therefore ensure conversion of alternating current into direct current.
The desired criteria for the chargers, and more particularly for the on-board chargers, are high efficiency, compact design, galvanic isolation, good reliability, safe operation, low emission of electromagnetic disturbances, and a low harmonic factor on the input current.
In order to implement the AC/DC conversion function with galvanic isolation, it is known to use a structure having two converters:                a first, AC/DC converter referred to as a pre-regulator, which comprises a power factor correction circuit in order to limit the input current harmonics.        a second, DC/DC converter to ensure the regulation of the charging. This DC/DC converter also provides the galvanic isolation function for safe use.        
There are two categories of on-board chargers: the most common category is that of on-board chargers having a single-phase input. Since the vast majority of available electrical installations are single phase, these chargers can easily be connected to a large number of available connection points. However, the available charging power is limited as a result of the limit on the voltage and on the intensity of the input current.
The second category is that of three-phase input chargers, which have a greater charging power. However, since three-phase electrical installations are rare, in particular in the case of individuals, these chargers can only function in especially dedicated electrical installations.
There is therefore a need for a charging device for powering batteries of motor-driven machines (and in particular electric motor vehicles) which can be connected to the greatest possible number of systems for connection to the electrical network and which is capable of charging batteries at high power when said power is available.